Preheating torch



Jan. 18,1927.

H. A. ANDERSON PREHEATING TORCH Filed Dec. 22, 192.3

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Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

HILDER A. ANDERSON, 0F MINNEAPOLIS, MINNESOTA, ASSIGNOR T0 MARR MANU- FACTURING COMPANY, 0F MINNEAPOLIS, MINNESOTA, A CORPORATION OF MINNE- SOTA.

PREH'EATING TORCH'.v

Application filed December 22, 1923.y Serial No. 682,247.

rlhis invention relates to improvements in torches particularly adapted for use in preheating metal articles preparatory to welding or' bending and forming', and more particularly relates to such torches of the liquid fuel burning type.

The particular object of the invention is toV provide a torch having an auxiliary atomizi-ng and mixing chamber through which the mixture of fuel-oil and air is blown under pressure, thereby causing it to become. thoroughly atomized and mixed before being jetted' into the combustion nozzle or chamber for subsequent combustion.A

In the drawings thereA has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claims which follow.

A further object is to provide means for feeding the oil which will allow a sulicient flow but will prevent irregular feed and the danger of extinguishingr the torch in case it is jarred or jolted.

Other objects of the invention will more ful-ly appear from the following description and the accompanying drawings, and will be pointed out in the annexed claims.

In the accompanying drawings forming part of this specification,

Figure 1 is a partial sectional view of my improved torch, showing the general construction thereof;

Figure 2 is a detail sectional view on the line 2 2 of Figure 1; and

Figure 3 is a detail sectional view on the line 3--3 of Figure 1.

In the selected embodiment of the invention here shown there is illustrated a torch, having an air pipe 4 communicatingwith a. suitable soluce of air supply, not shown, and also having a similar pipe 5 through which the iuel-oil is delivered to the atomizing and mixing chamber.

Means are provided at the upper ends of the-pipes 4 and 5 whereby the mixture of air and fuel-oil may be conveniently regulated and controlled so that it may be delivered to thetorch nozzle in the proper proportions required to provide a highly combustible mirturc. Such means consists preferably in thev provision of two independently operated control valves mounted in a suitable housing' 6 terminally secured to the ends of the pipes 4 and 5. The air control valve is of well'- lrnown construction, comprising preferably a tapered valve plug 7 rotatably mounted in a correspondingly tapered seat 8 and re-V tained therein by a compression spring 9 and threaded cap 10. The valve 7 is provided, at its upper end, with a reduced stem 11 upwardly projecting through the cap 10 und' having an voperating handle 12 mounted thereon. The lower portion of the valve is axially bored to provide a recess 13, and a communicating passage 14 is provided in' the wall of the valve, which, when the valve is in open position, as shown in Figure 2, registers with a port 15 provided in theY valve housing 6. The port 15 is in direct communication with a similar port 16 pro'- vidcd in a suitable4 coupling 17 having a tapered end portion 1-8 to which an ordinary hose may be connected, leading tothe source of air supply. Thus, when the tapered valve plug 7 is rotated, by means of the'handle 12, the communicating passage 14 may be moved in and out of registration with the port 15, as desired, thereby increasing or decreasing the flow kof a-ir to the torch nozzle.

As shown in F igure- 1, the lower ends of the-pipes 4 and 5, arel suitably secured' to a head 19, and in this headgis mounted the means for controlling the flow of fuel-oil to the torch nozzle. Such means consists preferably in the provision of a' cylindrical valive 01 secured to the lower end of a hollow stem 22 which is rotatably mounted within theV oil pipe 5. As shown in Figure 1, the valve 21 is snugly fitted within a recess 23 provided in the casing 19. A longitudinalslot or groove 24 is providedv in one: side of the valve through which the fuel-oil may pas from the enlarged recess 25, above the valve 21, and through a port 26 leading toa small chamber 27 surrounding the air nozzle 28. Anv air conduit 29 is centrally provided in the nozzle 28 and upwardly leads therefrom, Y

and has its upper end in direct communica- Ytion with the lower end of the air pipe 4.

pose of securing a positive shut-olf. The oil. is controlled by uncovering the upper portion of the slot 24 above the corner of the recess 23. Slotted openings 32 are preferably provided adjacent the lower end of the stein 22 to conduct the oil therefrom to the enlarged recess 25 above the valve 2l.

The upper end of the hollow stem 22 is suitably secured to the lower end of a threaded valve stem 33 rotatably mounted in a bonnet 34 secured to the housing 6. The upper end of the bonnet is threaded to receive a packing nut 35 adapted to engage a packing gland'or sleeve 36 to compress the usual/packing 37. A. hand wheel 38 is secured to the upper end of the valve stem 33 by means of which the slotted valve 2l may be actuated. Thus, it will readily be seen that by rotating the threaded valve stem 33, the threaded portion thereof will cause it to be Vmoved longitudinally within the bonnet 34 with the resultant opening and closing of the'cylincrical valve 21 at the lower end of the hollow stem 22. The outside diameter of the stem 22 is preferably slightly less than the bore of the pipe 5, so that it will not be in frictional contact therewith when rotated.

Elongated openings or slots 39 are provided in the stein 22 adjacent the upper end thereof, by means of which the oil may enter the stem; flowing downwardly therethrough and out of the similar openings 32 provided at the lower end thereof. A passage 4i leads from the upper slotted end of the stem 22 through the wall of the housing 6, to a suit- .abl-e filtering screen or cup 42 mounted in the housing. The oil is introduced into this filtering screen'from a conduit 43, outwardly and upwardly leading therefrom through a nozzle-like end portion 44, to which an vordinary hose, leading from the source of oil supply, may be connected. The filtering screen 42 is preferably cylindrical in form, and linay readily be removed by means of the threaded nut 45. Feeding the oil through the hollow stem 22 reduces resistance on account of reduced Contact areas, the duct inthe stem being of suflicient size to'allow the desired flow of oil without increasing resistance. This arrangement allows me to reduce the vohune of oil in the stem and prevent irregular feed in ease the torch is jarred or jolted, as T have found that themomentum of a large volume of oil will cause the torch to become extinguished in case of a sudden jolt or jar. This difficulty is entirely eliminated by feeding the oil through a duct having a comparatively small cross-sectional area.

An important feature of this invention resides in the novel means provided lfor thoroughly atomizing` the fuel-oil and mixing it with air before it is delivered into the combustion chamber or nozzle of the torch. As

shown in Figure l, the lower end of the torch head i9 has a reduced threaded end portion 46 concentrically formed thereon. The conically shaped air nozzle 28 is preferably integrally and concentrically formed on the lower face of the reduced end portion 46 ofthe head i9 adapted to partially project into one end of an atomizing chamber 48, centrally provided in an atomizing nut 49 which is internally threaded to receive the threaded end portion 46 of the torch head. rThe upper end of the atomizing chamber 48, in which the air nozzleY 28 is inserted, is preferably provided with a tapered bore corresponding to the taper of the nozzle 2S. The atomizing nut 49 is so constructed that when it is positioned upon the torch head, as shown in Figure l, the outer tapered wall of the nozzle will be out of contact with the correspondingly tapered bore of the atomizing chamber 48, thus providing an annular opening around the air nozzle 'through which the fuel-oil is drawn by the suction created by the high velocity of the air as it is blown into the atomizing chamber from the conduit 29 of the nozzle 2S. Tf desired, the atoinizing nut may be adjustably mounted on the torch head so that the annular opening' around the air nozzle may be increased Vor decreased in size. ln actual practice, however, I found that if the parts are so constructed and machined as to provide the proper size opening, that such adjustment is superfluous, and l therefore prefer to eliminate it in order that the torch may not be rendered inoperative as a result of improper adjustment, which might occur should such adjustment beI attempted by a novice or inexperienced person.

Another important feature of this invention is the auxiliary means provided for thoroughly mixing the atomized fuel-oil with the atomizing air and also reducing its velocity before it is discharged into the combustion chamber. An integral threaded end portion 5l` is provided on the lower face of the atomizing nut 49, adapted to receive one end of a cylindrical nozzle-like cap 52 cured thereto. This cap is bored to provide a relatively large auxiliary mixing chamber 53, having a restricted discharge opening 54 through which the mixture of fuel-oil and air is discharged into the combustion chamber 55. Thus, as the air is discharged, under pressure, into the atomizingchamber 48, the velocity of the air in passing therethrough will cause a vacuum to be built up in the annular opening around the air nozzle 28 and in the chamber 27, thereby causing a quantity of oil to be drawn into the atomizing chamber where it will be brolren up and atomized as a result of the high velocity of the air. As the mixture'of the thus atomized fuel-oil and air enters the relatively large mixing chamber 53,. it will tend to expand with the resultant retardation of its velocity. Such expansion of the atomized oil and air will cause the oil to be more thoroughly atomized and mixed wit-h the air, and as it is blown through the restricted opening 54 of the cap 52, a highly combustible fuel mixture will be discharged into the combustion chamber 55 for subsequent combustion and discharging from the usual discharge nozzle 56 of the combustion chamber 55. A. plurality of suitable air ducts 5'?, 58 and 59 are provided in the wall of the combustion chamber 55 through which a supply oi air may be drawn thereinto. The combustion chamber and nozzle 56 are provided with a cylindrical split sleeve 61 adaptedv to be fitted over the atomizing nut and the lower portion and is secured thereto by means able bolt 62.

ln the practical use of this novel torch, the pipes t and 5 function as a handle, by means ot which it may be conveniently carried about from place to place by the user. Its operation is controlled entirely by means of the hand lever l2 and hand wheel 38, thus providing a simple and convenient means for regulating and controlling the flow of oil and air in order that the proper amount of each may be delivered to the atomizing and mixing chambers to insure proper and eHicient combustion.

I claim as my invention:

l. A device of the class .described having a terminal tapered nipple, and a nut bored and counter-bored to provide axially alined chiots and connected with the head to provide an annular oil chamber of small capacity about an-d at the base of the nipple, and `forming therewith an attenuated conical outwardly convergent discharge orifice, converging into a mixing duct, in turn leading to a. terminal expansion or dischar e duct of greater calibre, having a slight y constricted delivery orifice, and valve-controlled oil and air supply ducts leading respectively to and through the annular chamber, and through the nipple to the mixing duct, the calibres of those portions of the oil and air supply ducts within the head being oi? substantially smaller calibre than the mixing duct.

2. A device of the class described, comprising parallel elongated air and oil supply pipes, spaced to form a handle, and secured at opposite extremities by intake and mixing and delivery heads, said intake head having supply ducts leading to respective pipes, valves for the ducts having stems axially alined to the pipes and operable from the outer end of the head, said delivery head bored and chambered for mixing oil and air and delivering the same through a terminal constricted orifice after expansion,

of a suitof the torch head 19' said delivery head also having a duct connecting the mixingxcham'ber with the air supply pipe, and further having an oilA supply du'ct leading to the mixing chamber, :md

`a hollow stem as an oil duct in the oil pipe translatable by rotation and having a valve controlling the oil supply duct to the mixing chamber and seating in a direction axially of the oil ipe.

3. A pre ieating torch comprising a head having air and' liquid fuel. ducts therein and a nozzle, a member forming. anL extension of said head and having an atomizing chamber therein and a bore to receive said nozzle, a space being formed between said nozzle and the wall of said bore communicating with said liquid fuel duct, said air duct communieating with saidy atomizing chamberA through said nozzle, the liquid fuel and air becoming mixed in said chamber adjacent said:

nozzle, and a cap encircling the exit of said chamber and having an expansion chamber therein and a slightly constricted discharge opening leading therefrom.

l. A device of the lclass described, comprising control and delivery heads connected by elongated air and oil pipes' spaced to form a handle or grip for supporting the device in operating position; valve-controlled supply ducts leading to respective pipes in the control head, said delivery head bored and counterbored to provide a pipe socket, an oil receiving chamber, and valve receiving bore of small calibre., having a valve seat at its juncture with the chamber, an elongated hollow valve-controlling stem and oil supply duct of small calibre Within the oil pipe translatable by rotation therein and extending through the oil chamber of the head, a valve member having one end socketed in the stem and adapted to engage at an intermediate portion VWith the valve seat, and an extension slidably itting the bore, and further having a longitudinal oil groove within the bore, said delivery head having supply ducts respectively leading from the bore and from the air pipe forwardly, said head havin a mixing duct to provide a mixing cham er for air and oil, which air and oil are delivered, and further having a terminal expansion chamber beyond the mixing duct,said chamber having a slightly constricted delivery orifice.

5. A preheating torch comprising a head having air and liquid fuel ducts therein and a nozzle and a mixing chamber, said head having a recess therein to receive said nozzle and also provided with an atomizing chamber in alignment with said nozzle and of greater cross sectional area than the duct in said nozzle, and said head also having means provided with an expansion chamber forming an enlarged continuation of said atomizing chamber having a terminal, slightly constricted, delivery orifice, the liquid fuel being thoroughly atomized in said atomizing and expansion chambers before delivery to said mixing chamber.

' 6. A preheating torch comprising a head having` a mixing chamber therein, means for delivering air to said head, a liquid fuel pipe having one end secured to said head and its other end connected to a source of liquid fuel supply, a duct Connecting said fuel pipe with said mixing chamber, and a hollow stem ot' comparatively small crosssectionalrarea mounted in said liquid fuel pipe and having a connection With a valve mechanism mounted in said head, Wherel y the supply of fuel to said mixingchamber may be regulated, the comparatively small cross-sectional area of said stem insuring regularity of fuel feed to said head as a result of the small body of fuel oil contained therein.

7. A device of the class described, coniprising intake and delivery heads connected by Oil and air pipes, said delivery head having an intermediate mixing chamber and a terminal expansion and delivery chamber, a valve stem and oil delivery conduit Within the oil pipe having a valve seating in the delivery head and controllable from the receiving head for the purpose speciiied, said receiving head having oil and air supply ducts connecting with the stem and air pipe, and said delivery head having ducts respectively connecting said air and oil pipes with its mixing chamber, said oil duct being of smaller calibre than the air duct and leading to said mixing' chamber at a pointin the rear of said air duct.

In Witness whereof, I have hereunto set my hand this 18th day of December 1923. HILDER A. ANDERSON. 

